feat(web): add Mappings page with inline CRUD table

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

TaskTracker.Api/Pages/Mappings.cshtml

@@ -0,0 +1,48 @@
+@page
+@using TaskTracker.Api.Pages
+@model MappingsModel
+
+<div class="mappings-page">
+    <div class="analytics-header">
+        <h1 class="page-title">App Mappings</h1>
+        <button class="btn btn--primary btn--sm"
+                hx-get="/mappings?handler=AddRow"
+                hx-target="#mapping-tbody"
+                hx-swap="afterbegin">
+            + Add Rule
+        </button>
+    </div>
+
+    @if (Model.Mappings.Count == 0)
+    {
+        <div class="surface empty-state">
+            <p style="color: var(--color-text-secondary); font-size: 14px; margin-bottom: 12px;">No mappings configured</p>
+            <button class="btn btn--ghost"
+                    hx-get="/mappings?handler=AddRow"
+                    hx-target="#mapping-tbody"
+                    hx-swap="afterbegin">
+                + Add your first mapping rule
+            </button>
+        </div>
+    }
+
+    <div class="surface" style="padding: 0; overflow: hidden;">
+        <table class="mappings-table">
+            <thead>
+                <tr>
+                    <th>Pattern</th>
+                    <th>Match Type</th>
+                    <th>Category</th>
+                    <th>Friendly Name</th>
+                    <th style="width: 96px;">Actions</th>
+                </tr>
+            </thead>
+            <tbody id="mapping-tbody">
+                @foreach (var m in Model.Mappings)
+                {
+                    <partial name="Partials/_MappingRow" model="m" />
+                }
+            </tbody>
+        </table>
+    </div>
+</div>